chopping knife vs chopper knife

chopping knife and chopper knife both are nouns.

Word	Noun	Adjective	Verb	Adverb
chopping knife	Yes	No	No	No
chopper knife	Yes	No	No	No

As nouns, chopping knife and chopper knife are synonyms defined as:

chopping knife and chopper knife: a considerably big knife used for chopping or mincing meat, vegetables, etc.

chopping knife (noun)	chopper knife (noun)
a considerably big knife used for chopping or mincing meat, vegetables, etc.	a considerably big knife used for chopping or mincing meat, vegetables, etc.